MADISON - For the third time this week, a potential challenger to GOP Gov. Scott Walker has ruled out a 2018 run against him.

This time it's Madison tech executive Mark Bakken, who had been getting attention from Democrats because of his success founding an IT consulting company and because he could have brought formidable financial resources into a race.

In phone calls to close associates Friday, Bakken ruled out a run and said he would focus instead on his business ventures, according to sources who spoke directly with Bakken. The decision increases the chances that trial attorney and state Rep. Dana Wachs (D-Eau Claire) could announce a run against Walker, since Wachs is a friend of Bakken's and would have been unlikely to run against the executive.

One of the sources who spoke with Bakken said that the businessman was reluctant to leave his venture fund, HealthX Ventures, for the rough and divisive world of politics.

"It's not the right time for Mark to step away from that work, when the companies HealthX is developing and his investors are counting on him to deliver," the source said.

Bakken did not respond to a request for comment on the decision.

On Wednesday, Democrat Tim Cullen, a former Senate majority leader and business executive, said he wouldn't run in 2018, citing the grind of fundraising calls that would have been needed. On Friday, former Green Bay Packer Mark Tauscher put an NFL-sized block on rumors he would run for governor.

"Yet again, Democrats are taking a pass at running against Governor Walker's strong record of results and reform because they lack an agenda of their own," campaign aide Joe Fadness said.

But Wachs was disappointed, saying that Bakken had "a lot to offer our state." Wachs said he'd need to think more about his own campaign now that Bakken isn't running

"My family and I and my close confidants need to talk through (this)," Wachs said. "Stay tuned."

Though untested in politics, Bakken had been considered a high-level possibility for Democrats because he co-founded and served as chief executive officer of Nordic Consulting Partners, a firm that helps health care organizations that use the software of another Madison area company, Epic.

The growing company now employs hundreds of highly paid workers and last year the website Healthcare Informatics pegged Nordic's annual revenues at $137 million. That gave Bakken, who left Nordic in November 2014, both business credentials and sizable personal wealth to draw on for a campaign if needed.

But Republicans were already looking into an undecided sexual harassment case which involved another former Nordic executive and a female former employee.

The ex-staffer contends she was let go in February 2014 not long after she informed Bakken that she was the subject of unwanted sexual comments and conduct by the company's other executive.

The company is disputing the allegation. A judge with city of Madison Equal Opportunities Commission is expected to issue a decision on the complaint later this spring.